Electric switch



Jan. 2, 1945. P HUTT 2,366,530

ELECTRIC SWITCH Filed March 18, 1943 Fig. z.

IIIII'IIIIH mmmmumlmll 47 y Inventor:

. ph i li Hutt Fl 6. P al@ by 7M His Attorney.

Patented Jan. 2, 1945 ELECTRIC SWITCH Philip Hutt, Milford, Conn., assignor to General Electric Company, a corporation of New York Application March 18, 1943, Serial No. 479,619

(Cl. 20G- 67) 4 Claims.

The present invention relates to electric switches and like devices of the toggle operated or tumbler type.

The object of my invention is to provide an improved switch and like device which is corn pact and rugged in construction and especially adapted for heavy duty operation.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing.

In the drawing, Fig. 1 illustrates a plane view of a switch embodying my invention; Fig. 2 is a section along line 2 2 of Fig. 1; Fig. 3 is a top view of the switch with a casing part removed; Fig. 4 shows an assembly of the switch with a. supporting bracket; Fig. 5 is an exploded perspective view of the switch elements; and Fig. 6 is a perspective view of one of the switch elements. f

The switch has a molded insulating casing l composed of a lower part or half II and an upper part or half I2 (Fig. 2) secured together by means of two screws I3 each having a head located in a recess |4 formed in the bottom of part and an end portion screwed into an opening I of a bracket I6 for supporting the switch on a wiring box or like support. The lower or bottom part II and the upper part or top I2 of the casing have four aligned bores I1. The lower casing part has a rectangular recess I 8 in its bottom and abutments I9, on opposite side walls near the bottom of the lower half.

The switch includes a toggle mechanism for operating movable contacts. This toggle mechanism according to my invention forms a unitary structure which in its operation is not dependent upon the casing. This unitary structure, as best shown in Fig. 5, comprises a frame 2| essentially U-shaped having a base 22 rectangular in shape and fitting into the rectangular recess` I8 in the bottom of the lower casing part II. Each leg of the U-shaped frame 2| forms a lower bearing 23, an upper knife-edge support 24 and stops 25, 25. A U-shaped bladecarrier or operating lever 21 is associated with and supported on the frame 2|. The legs of the lever 21 have trunnions 28 for engaging the bearings 22 of the frame and short projections 29 adjacent the trunnions 28 located adjacent the outer surfaces of the legs of the frame and preventing lateral movement of the lever 21 relative to the frame 2| The legs of the lever 21 have lateral rectangular projections 30 for receiving and carrying movable contact 55 assemblies. The base of the lever 21 in one end position engages the stops 25 and in the other end position the stops 26. The lever 21 may be moved from one end position into the other by means of a trigger. This trigger includes an arm 3|, an overcenter spring 32 and a handle 33. The arm 3| has two diametrically opposite portions 34, laterally oiset from a central plane throughv the handle and depending fromv the handle 33 and secured thereto by means of screws projecting through openings 36. The lower ends of the portions 34 are united by a cross-bar 31 having an opening 38 and extending perpendicular to said central plane. Each portion 34, 35 at its upper end forms a projection or trunnion 39 extending laterally from the bottom of the handle 33. These projections when assembled are inserted into openings 40 of the frame to engage the knife-edge bearings 24. The spring 32 is connected at one end through the opening 38 to the bar 31 of the arm 3| and at its other end to a. notch 4I lin the base of the lever 21. The offsetting of the portions 34, 35 of the arm 3| from the central plane through the frame 2| and the U shape of the lever 21 provide lfor free movement of the spring 32 in the space formed between the lever 21 and the arm 3 I.

During operation the lever 21, as pointed out above, engages in an end position the stops 2S. In this position the arm 3| engages a stop 42 formed on the frame 2|. At the same time the projections 39 of the arm 3| are limited from further turning movement in the openings 40 of the frame (Fig. 2). If now the handle 33 is 4forced upward against the increasing tension of the spring 32 the lever 21 is snapped into its other end position in which it engages Athe stops 25 as soon as the centerline of the spring passes the centerline of the lever 21.

During assembly the arm 3| is fastened to the handle 33. Thereupon an end of the spring 32 is passed through the opening 38 of the bar 31 to complete the trigger. The trigger then is assembled on the frame 2|, the legs of the frame being slightly biased apart so that the projections 39 of the arm may be inserted into the openings 40 of the frame. When assembled on the frame the trigger is placed into an end position. The lever 31 is then inserted into the frame and connected to the other end of the spring 32. This completes assembly of the toggle unit which, as pointed out above, is self-contained', that is, does not depend in its operation on cooperation with the casing or a part thereof. When assembled with the casing the free end portions 42a of the legs of the frame t into recesses 42h (Fig. 1) in the upper casing half and thus are prevented from spreading apart.

The lateral projections 30 of the operating lever or blade carrier 21 serve to carry movable contact assemblies 43 and 44 respectively. Each movable Contact assembly 43, 44 comprises two spaced contact plates 45 engaging opposite surfaces of a pair of spaced insulating arc snuiers or arc-shutting disks 46. The latter have adjacent surfaces with lower portions engaging a spacer 41 (Fig. 6). The plates 45, the disks 46 and the spacer 41 are secured together by means of a pair of rivets 46. The disks 46 and the spacer 41 have aligned rectangular openings or slots 49 which form a snug fit with the lateral projections 30 of the lever 21. The movable contact plates 45 also have rectangular openings 50 aligned with but larger 'than the openings 49. The disks 46 and the spacer 41 are made of insulating material. Hence, the contact plates 45 are insulated from the lever 21. Each contact plate 45 has a pair of circumferentially spaced fingers and 52. The disks 46 adjacent the iingers 5| are cut away to form openings 53 and the fingers 5| are bent toward each other with their adjacent surfaces spaced slightly less than the spacing of the disks 46 or the thickness of the spacer 49. The disks 46 form other openings' 54 adjacent the lingers 52, which latter are likewise bent inward with their adjacent surfaces spaced less than the spacing between the disks 46.

The two contact assemblies 43, 44 are alike. in the present example the switch is intended as a 3-way switch. Therefore, as indicated in Fig. 5, the contact assembly 44 is turned inside out relative to the assembly 43 so that one of the assemblies will open when the other closes or makes Contact and vice-versa.

According to my invention a stationary arcquenching barrier 55 is associated with each contact assembly. The barrier 55 like the disks 46 is made of fiber or like insulating material. It is essentially U-shaped and located between the pair of disks 46, that is, straddling the spacer 48 without engaging the latter, and supported with the ends of its legs on the bottom of the casing. The base of the U has cut-away portions forming openings 56 and 51 for receiving stationary contacts, as more fully described hereinafter.

During operation the contact fingers 5|, 52 in one position as shown with regard to the contact assembly 43 face and are separated by portions of the barrier 55. In another position the movable Contact lingers 5| face the openings 56, 51 of the barrier and in this position may be electrically connected to stationary contacts located in said openings 56, 51. After the movable contact assemblies with the toggle unit are inserted in the lower casing portion the barriers 55 are placed between the disks 46 of each movable contact assembly. Thereupon the stationary contact assemblies may be assembled on the lower casing half. In the present instance three contact assemblies 58, 59 and 60 are provided. Each of the three contact assemblies comprises a ter minal block 6| preferably made of copper or brass tubing by a forming operation. One end wall 62 of the essentially rectangular block 6| is pointed. Another end wall 63 opposite the pointed wall 62 has a threaded opening 64 for receiving a screw 65 which latter has a head provided with a collar 66. The blocks 6| are disposed in recesses 61 formed in the lower and upper casing portions. The screws 65 are threaded into the opening 64 with the collar 66 of the screws disposed in annular recesses 66 formed in the lower and upper casing portions to limit axial movement of the screw. The slots 61 are longer than the blocks 6| so that the latter may be slid along the slots 61 by turning o! the screws 65. The stationary contact assembly 66 in addition to a block 6| and a screw 65 comprises a terminal plate 69 which is attached to and properly positioned on the lower casing portion by means of two self-tapping screws 10 and two bosses 10a on the casing fitting two recesses 10b on the plate 69. The terminal plate 69 has opposite end portions provided with contacts 1| and 12 which when assembled are located in the openings 56 of the barriers 55 and adapted to engage the pair of fingers 5| of the movable con tact assemblies 43 and 44 respectively. The terminal plate 69 has a lug or tang 13 which fits into the opening of the block 6| and upon tightening of the screw 65 may be electrically connected to the block and to the bare end of a wire inserted through an opening |1 from the back oi the casing into the opening of the block near the pointed endA portion 62. During assembly the block 6| with the screw 65 are placed into the recesses 61, 66. Thereupon the terminal plate 66 is attached to the lower casing portion by the self-tapping screw 10 with the tang 13 projecting into the opening of the block 6| and the contacts 1|, 12 located in the openings 56 of the barrier plates. After the switch is completely assembled the bare end of a wire to which it is to be connected may be inserted from the rear through an opening l1 into the opening of the block 6|. Tightening of the screw 65 then forces the block with the bare end of the Wire towards the tang 13 of the terminal plate 69.

Each of the stationary contact assemblies 66, 60 includes a similar block 6| with a screw 65 and a terminal plate 14 and 15 respectively. Each of the plates 14, 15 has a central portion with an opening 16 for attachment to the lower portion of the casing by a self-tapping screw 11 and a recess 11a for engaging a. boss 11b on the casing to properly position the terminal plate. One end portion of each terminal plate 14 forms a Contact 18 and the other end portion forms a depending lug or tang 19 for cooperation with the corresponding terminal block 6|. When assembled the tang 19 of the assembly 60 is located in the opening 51 of the barrier plate 55 for cooperation with the contact fingers 52 of the stationary contact assembly 43 and the corresponding contact of the assembly 59 is cooperatively associated with the contact fingers 52 of the movable contact assembly 44. After the stationary contact assemblies are attached to the lower casing portion the upper casing portion I2 may be fastened to the lower portion by means of the screws I5 and the supporting bracket I6.

During operation one of the movable contact assemblies 43. 44 connects the stationary contact assembly 58 with one of the other stationary contact assemblies 59, 60 while the other movable contact assembly is in open position. The switch like other 3-way switches may be used as a singlepole switch and may be readily changed into a. 2-pole switch by the provision of separate stationary contact assemblies corresponding to the assemblies 59, 60 in place of the assembly 56. The use as a double-pole switch also requires inside-outside turning of one of the movable contact assemblies 43, 44 so that during operation the contact fingers 5|, 52 of each assembly connect simultaneously with the corresponding stationary contact assemblies. During operation arc formation between the stationary and movable contacts is reduced to a. minimum by cooperation between the movable arc-snufing disks 46 and the stationary arc-quenching barriers 55. As the movable contacts break away from the stationary n contacts the rst are moved onto opposite sides of a portion of the barrier 55 while the latter, that is, the stationary contacts, are enclosed between opposite portions of a pair of arc-snufng disks I6.

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that the invention may |be carried out' by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric switch comprising an insulating casing having a chamber, a plurality of stationary contact assemblies secured to the casing, movable contact assemblies for cooperation with the stationary assemblies disposed within the casing and a unitary toggle structure for actuating the movable contact assemblies, said unitary toggle structure comprising a handle, an arm secured to the handle and having two portions offset in opposite directions from a central plane through the handle with the outer ends Aof these portions united and forming a bar with an opening .extending perpendicular to said central plane, a frame loosely seated on the bottom of the cham'- ber having side walls located outside of and forming a bearing for the arm near the handle and stops for engaging the arm near the cross-bar, a blade carrier supported on the frame and adapted to engage other stops formed on the frame, and an overcenter spring biasing the carrier towards the cross-bar.

2. In an electric switch of the toggle operated type, a movable contact assembly comprising a pair of spaced insulating snuiling disks each having two spaced openingsv near its periphery, a pair of contact plates secured to opposi surfaces of the disks and having contact fingers located in said openings, the insulating disks having aligned rectangular openings, a. togglevmechanismwith a carrier having an arm projecting through the aligned openings for moving the movable contact assembly from one end position to another, a stationary .arc-quenching barrier having a pair of spaced openings being located between the arcv snufllng disks and a pair of stationary contact assemblies with contacts located in the openings of the barrier and adapted to be engaged by the `fingers of the movable assembly in one end position thereof, the fingers of the movable assembly in the other end position being located on opposite sides of a portion of the barrier.

3. In an electric switch an insulating casing, a toggle structure with movable contact assembly means supported on the casing, and a stationary contact assembly supported on the casing for cooperation with the movable contact assembly, said stationary contact assembly comprising a terminal plate, screw means and a projection on the casing engaging a recess of the terminal plate for securing and positioning the terminal plate on the casing, the plate havinga contact for coop- I eration with the movable contact assembly means, a substantially rectangular contact block with an opening slidably held in a recess of the casing, a tang formed on the terminal plate projecting into said opening and a screw threaded into an opening of the block andI having a collar engaging a shoulder. on the block to slide the block into elec-- trical engagement with the tang.

4. An electric switch comprislnga casing, a unitary toggle structure supported on the casing and including a frame, a ltrigger with an arm having members supported on the frame and adapted to engage stops formed on the frame. a spring-biased lever held on the frame and forml ing .a pair of rectangular trunnlons, a pair of movable contact assemblies supported on the trunnions, each assembly having a pair of spaced arc-snuillng disks and contact plates supported on opposite sides of the disks with fingers projecting through adjacent openings of the disks, arc-quenching barriers loosely supported on the casing and being locatedbetween the arc-snulng disks of each assembly, and stationary contact assemblies supported on the casing and having contacts projecting into openings formed by the barrier between the arc-snuillng disks.

PHlLIP HUTI. 

